1. Field of the Invention
The present invention relates to an optical information recording method and apparatus for recording data on an optical information recording medium that includes plural recording layers each having a data area for recording information, an information processing apparatus implementing such an optical information recording apparatus, an optical information recording medium that includes plural recording layers each having a data area for recording information, a program that is run on a computer of an optical information recording apparatus to administer data recording on the data areas of such an optical information recording medium, and a recording medium storing such a program.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 2001-126255 discloses an information recording apparatus that records data on an optical information recording medium having plural recording layers, wherein recording is conducted on the recording layers starting from a recording layer that is positioned away from a light incidence side with respect to the other one or more recording layers of the medium in order to prevent degradation of the quality of the recorded data.
Examples of recordable disks conforming to the DVD standard include the DVD+R. A DVD+R has physical characteristics that are similar to those of a DVD-ROM, and can thereby maintain good compatibility with a DVD-ROM drive. Since the DVD+R corresponds to a write-once medium that does not allow rewriting of data, data are sequentially recorded in the DVD+R.
To enable a DVD-ROM drive to read data that are recorded as files, an area for recording file information is reserved at the beginning of a session, and when the session is closed, the file information of the recorded data is recorded in the reserved area according to a conventional method.
As is described above, data are sequentially recorded in the DVD+R from the inner radius side of the disk. In such case, by dividing the recording area of the disk into plural tracks (in the DVD+R the tracks are referred to as fragments), and recording data on these tracks, a front area of a session may be recorded later.
Also, even when a session is closed, a new session may be added so that additional data may be recorded after closing a session. Such recording methods used by the DVD+R are referred to as a multi-track recording method and a multi-session recording method.
Presently, much research and development are being conducted to increase the speed and capacity of recordable disks such as the DVD+R. As one exemplary proposal for achieving such objects, a one-sided dual layer DVD+R having two recording layers on one side (referred to as dual layer DVD+R hereinafter) that is capable of maintaining playback compatibility with a one-sided dual layer playback-only (read-only) DVD is provided.
The dual layer DVD+R has a storage capacity of 8.4 Gbytes, whereas a conventional single-layer DVD+R has a storage capacity of 4.7 Gbytes. This means that the storage capacity of the dual layer DVD+R is nearly double the storage capacity of the convention single layer DVD+R. The data recorded on the dual layer DVD+R may be read by a DVD player or a DVD-ROM drive that is capable of replaying a dual layer playback-only (read-only) DVD.
In a dual layer DVD+R, a logical address is successively assigned from the start address of a first recording layer data area, and a consecutive logical address continuing from the logical address assigned to the end address of the first recording layer data area is assigned to the start address of the second recording area data layer. Accordingly, upon recording data on a dual layer DVD+R, a user may not have to be aware of the existence of two separate recording layers.
In recording data on a dual layer DVD+R, the data areas of the recording layers of the DVD+R are divided into plural divided areas that may correspond to fragments or sessions, for example. In such case, the division into divided areas is preferably realized in a manner such that a user may not have to be aware of the existence of two separate recording layers.
For example, in the case of dividing the data areas into fragment units, the user may designate a fragment size according to a conventional fragment division method. Accordingly, an incomplete fragment corresponding to a last fragment within a data area is divided into a reserved fragment having the designated size and a new incomplete fragment.
In a case where the start address of the last fragment is located within the data area of the first recording layer, the reserved fragment may extend beyond the first recording layer data area depending on its prescribed data size. However, since the first recording layer data area is fixed, data may not be recorded beyond the first recording layer data area.
The existence of such restrictions on fragment division means that a user has to keep track of the range of the data areas of the recording layers. This in turn creates an inconvenience for the user.